Abstract
Single-nucleon knockout cross sections from fast secondary beams of the proton-drip-line nuclei , , and on a target have been studied with emphasis on the production of resonance states. These states were identified by their invariant mass, and resonances with two-, three-, and five-body exit channels were examined. The measured cross sections for these states were compared with eikonal-model predictions using shell-model or variational Monte Carlo spectroscopic factors. The experimental yields were found to be suppressed relative to the model predictions, especially when a well-bound neutron or proton is removed. This suppression exceeds that found systematically in measured inclusive cross sections to particle-bound final states. In neutron knockout from and projectiles, this suppression of the unbound ground-state residuals yield is a factor of two to three times larger than that found in the bound final-state studies. Modifications to the structure of these systems due to coupling of the shell-model configurations to the continuum is expected to contribute to this extra suppression, especially when the final state is a near-threshold resonance. However, other considerations including the role of nuclear dynamics may be required to explain all the observed trends.
9 More- Received 16 July 2020
- Accepted 29 September 2020
DOI:https://doi.org/10.1103/PhysRevC.102.044614
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